Cushioning device for sheet-metal presses



Oct. 14-, 1930. F. J RODE 1,778,229

CUSHIONING 'DEVICE FOR SHEET IETAL PRESSES Filed May 25, 1929 {Sheets-Sheet l Oct. 14, 1930. F. J. RODE 1,778,229

CUSHIONING DEVICE FOR SHEET METAL PRESSES Filed llayv25, 1929 4 Sheets-Sheet 2 Oct. 14, .1930. v F. J. RQDE I ,778,

I I CUSH'IONING DEVICE FOR SHEET METAL PRESSES Filed May 25, 1929 4 Sheets-Sheet 3 -IIIIIIIIIIIINIIIIL\ I\\\\\\ Oct..14, 1930. F. J. RODE 1,778,229

CUSHIONING DEVICE FOR SHEET METAL PRESSES Filed May 25-, 1929 4 Sheets-Sheet 4 Patented Oct. 14, 1930 UNITED STATES PATENT OFFICE FREDBICfi J. BODE, OI CHICAGO, ILLINOIS, ASSIONOB TO MARQUETTETOOL & -MFG.

COMPANY, 01 CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS OUSHIONING DEVICE FOR SHEET-METAL PRESSES Application filed Kay 25,

This invention relates in general to cushioning devices, but more specifically to pneumatic cushions for presses .of the type in which the metal is shaped by means of cooperating dies, one of which is reciprocable toward and away from the other, the work being clamped or held by means of a blank or work holding element which co-operates with the reciprocable die member, the blank. or work holder being resisted in its movement in one direction by a pressure pad, the latter being resisted by the fluid pressure in thecushion, .andQQIle of the objects of theinvention is to provide in a pneumatic cushion of this character improved means for controlling the return of the pressure pad whereby the latter may be prevented from directly returning with the ram of the press or the cooperating die, when the latter starts to move A further object is to provide improved means for controlling the return of the pressure pad.

To the attainment of these ends and the accomplishment of other new and usefulobjects as will appear, the invention consists in the features of novelty in substantially the construction, combination and arrangement of the several parts hereinafter more fully described and claimed and shown in the accompanying drawings illustrating this invention, and in which Figure 1 is a view partly in elevation, partly in section, partly brokenaway and with parts omitted, of a sheet metal press having a cushion and control mechanism constructed in accordance with the principles of this invention, applied theret Figure 2 is an enlarged detail vertical sectional view of the cushion proper. I

' Figure 3 is a'yiew on an enlarged scale taken on line 3-3, Figure 1.

Figure 4 is a view taken on line H, Figure 3.

Figure 5 is a detail sectional view taken on line 5--5, Figure 4.

This invention is adapted for use with either whatis known as a single acting or a double acting press and in' either application of the invention, suifice it to say the press is 1929. Serial No. 866,982.

provided with a reciprocating ram movable on upright guides 11, a crank shaft 12 being provided for reciprocating the ram and carried by the ram is a die member 13 which co-operates with a die member 14; mounted upon a bed plate 15- supported by the bed 16 o the press.

Carried also by the ram 10 and movable with and with respect to the ram in any well known manner is a die member 17 which cooperates with a die member 18, the latter being supported preferably by means of pins 19 that pass loosely through the bed plate 15 and engage and rest upon a pressure pad 20, the latter operating in an opening 21 in the bed 16 of the press.

Arranged beneath the press bed and spaced a suitable distance therebelow is a support 22 which is held in position in any suitable manner and mounted upon this support are a plurality of cushion elements, any number of which may be provided, and as the construction and operation of each of the cushion elements is the same the specific description of one will apply to them all.

Each of the cushion elements embodies superposed cylinder elements 23-24 separated from each other by means of a partition 25 forming one of the heads of the cylinders.

Reciprocable in the respective cylinders are pistons 26-27 connected by means of a piston rod 28 that passes through a suitable stuffing box 29 in the head 25. The piston rod 28 is provided with a passage 30 opening through the end thereof forming communication with one of the cylinders and also opening laterally through the piston rod 28 as at 31 so as to form communication between the superposed cylinders 23-24; beneath the respective pistons 26--27.

A piston rod 32 is also connected with the pistons and the rod 28 and passes through a cation with each other through a connecting pipe 37.

The pipe 37 is connected'by means of a suitable connection-38 with a supply pipe 39, which in turn is connected by means of a branch pipe 39*, leading from a tank or container 40, the latter receiving a supply of fluid under pressure by means of a suitable supply pipe 41' leading from a suitable source.

The air or fluid passing through the pipe 39 will be delivered into the lowermost cylinder 23 of the cushion and a portion of the air will flow through the passage 30 out of the opening 31 into the cylinder 24 beneath the piston 27 to form a resistance pressure to the pressure pad 20 when the latter is lowered to cause the pistons 27-26 to be lowered in the cylinders and thereby yieldingly resisted in their downward movement by the pressure of the fluid in the cylinders 23.

The cylinders 23-24 are respectivel provided with inlet openings 42-43 whic may be connected by means of a pipe 44 which in turn is connected by means of a pipe 45 with a supply pipe 46, so that at a predetermined time in the cycle of operation of the press fluid under pressure will be. ad-

mitted into the cylinders 23-24 above the pistons 26 and 27 to neutralize or overcome the pressure of the fluid beneath the pistons 27 and thereby retain or hold the pistons 26-27 at the limit of their lowermost movements to prevent the pressure pad 20 from-directly following the ram 10 when the latter starts to ascend.

'All of the above referred to parts are of the ordinary and well known construction but are specifically described herein in order that a full understanding of the present invention as applied to such a type of cushion. will be had. I I

If desired, the respective cylinders of the cushions may be connected in the manner shown, that is in groups so as to increase-the I efliciency of the device and thereby obviate the necessity of superposing a number of cylinders.

As shown more clearly in Figure 2 of the drawings, one set of cylinders or cushions have communication with the pipe 46 through which fluid is supplied to and permitted to escape from the upper side of the respective pistons 26-27. Another set or series of the cylinders have communication on the upper side of the respective pistons 26-27 with a pipe 47 which in turn has communication with a pipe 48 and through the medium of a pipe 49 has communication with a. pipe 50,

through which latter air or fluid may be supplied to the respective cylinders on the top sides of the pistons and allowed to escape therefrom.

In order therefore to control the operation of the cushioning device in so far as the return of the pressure pad 20 and the respective pistons 26-27 is concerned, it is only necessary to control the flow of the fluid through the pipes 46-50 and this may be so regulated or controlled as to permit air (preferably from the atmos here to enter the cylinders on the top si es 0 the pistons to prevent the formation of a vacuum or partial vacuum on the top sides of the cylinders ,and subsequently to permit fluid under pressure to enter the cylinders on the top sides of thepistons to overcome the fluid pressure under the pistons and thereby retain the pistons in their lowermost positions, after which the fluid pressure on the top sides of the pistons is released and allowed to escape (preferably to the atmosphere that the pressure on the bottom sides 0 the pistons "will return the pistons and conse quently the pressure pad 20 to their normal positions.

To that end there is provided a valve casing 51 which is provided with a series of openings 52-53-54 and 55. To the opening 53 is connected one end of the pipe 39 and to the opening 52 is connected the extremity 39 I of the pipe 39*.

To the opening 54 is connected one end of the pipe 50 while to the opening 55 is connected one end of the pipe 46, as shown more clearly in Figure 5 of the drawings.

Arranged within the valve casing 51 is a passage 56 formed by partitions and the walls of the passage are provided withopenings 57-58 therethrough controlled respectively by means of valves 59-60.

' Two sets of these valves, each comprising one of the valves 59 and one of the valves 60. are provided for the following purpose. One set of the valves 59-60 controls the supply of the fluid and the exhaust of such fluid from the top sides of the pistons in one group of the cylinders and the other set of the valves 59-60 controls the supply of fluid to of the pistons in the other group of cushion cylinders, and as the operation of each set of the valves is the same the specific description of one set willapply to both.

Referring more particularly to Figure 3, the valves 59-60 therein illustrated control the supply of fluid to the top sides of one set of the pistons for holding the pistons down at the limit of their lowermost stroke and this set of valves is arranged to operate with respect to-the other set of valves which controls the fluid to the other set of the piston, andvice versa, so that the operation of one set will not interfere with the other.

The valves shown in Figure 3 are in the position they will assume when the ram is at the limit of its uppermost movement soas to establish communication between the the atmosphere to permit the fluid on the top sides of the piston to escape, the pistons having reached their uppermost position by reason of the fluid pressure beneath the pistons and the pressure pad 20 will be at the limit of its uppermost position or as shown in Figure 1, that is so that the air on the top sides of the pistons will escape to the atmosphere through an exhaust pipe 61 leading from the valve casing 51, as the valve 60 will be open permitting the air to flow through the pipe 60 into the valve casing 51 through the passage 58 and out of the 'exhaust pipe 61. The valve 59 controlling the supply of fluid to the top sides of the pistons from the tank or container 40 being closed.

When the valve 59 is opened the valve 60 will be closed and this will open the passage 57 in the valve casing 51 so as to permit the fluid under pressure to flow from the container 40 through the supply pipe 39" through the end or branch 39 of the pipe 39 into the valve casing through the passage 57, into the passage 56 and from the passage 56 ifito the pipe 46 and thence to the cylinders on the top sides of the pistons.

This will occur at the time just before the pistons 26-27 reach the limit of their lowermost movement.

'with. the valves just described so that an equal or uniform pressure will be supplied to all of the cushions on the top sides of the pistons at the same time.

- operating The fluid pressure from the top sides of the pistons will be exhausted from all of the cylinders at the same time by the simultaneous operation of the respective controlling valves.

' Any suitable-means may be provided fo the valves 5960, but preferably as follows.

a' spring 62 for controlling themand which springs operate upon the respective valve stems 63-434.v

A rocker member 65 is provided for operating each pair of'valves 5960. This member 65 is preferably pivotally supported intermediateits ends as at 66 and is provided preferably with portions 67 adapted to engage the ends of the respective stems 6364.

Anti-friction rollers 68-69 may be provided on the member 65 and theserollers 68-69 are laterally offset with respect to each other so as to be respectively engaged by cams 7 07 1 by the rotation of a supporting member 72 to which the cams are connected. These cams 7 0'71 are also laterally offset with respect to each other and are positioned at any desired angle with respect to each other about the member 72 so that when the member 72 is rotated in the direction indicated by the arrow in Figure 3 and with the valves in the position as shown in said figure, the cam 70 will engage the anti-friction roller 68 to rock the member 65 so as to open the valve 59 against the stress of its spring and permit the valve to close under the stress of its spring.

This will position the anti-friction roller 69 so as to be engaged by the cam 71 on the member 72 when the latter is further rotated and when the anti-friction roller 69 is engaged by its cam the member will be again rocked to the "position shown in Figure 3, to open the valve 60 and permit the valve 59 to be closed.

Thus it will be seen that the valves 59-60 will beralternately opened and closed at predetermined times in the cycle of operation of the press according to the osition of the cams 70-71 on the member 2. To change the time in the cycle of operation at which the valves operate, it is only necessary to reposition the cams 70 and 71 upon the supporting member 72.

Obviously, one of these rocker members 65 and one .of the operating members 72 with its respective cams 70 and 71 is provided for each set of'valves 5960.

The operating valve mechanism and the valve casings may be mounted upon a suitable support 7 3 which in turn may be mounted upon a bracket 74.

The rocker member 65 may be provided with an arm 75 to which an anti-friction roller 76 is connected. A spring pressed abutthe conical extremity 78 thereof under the f Each of the valves 59-60 is provided with m uence 0 1e Sprmg 79 W1 1 assist m Shlft ing the member 65. That is, after the movement of the member 65 has been started by the cam, the spring 79 forcing the abutment 77 and the conical face 78 against the roller- 7 6 will continue the movement of the memwhich passes over a suitable sprocket wheel connected with the member 72 and also over a suitable sprocket wheel 81, which latter is 1 connected .withany rotatable part of the press, preferably the crank shaft 12.

The cams and 71 may be secured to. the member 7 2 for adjustment with respect thereto in any suitable manner preferably by means of a fastening bolt 82 which passes through a suitable slot 83 in the member 72 and is anchored in any suitable manner. The member 72 may be provided with flanges 84 between which the base 85 of the cam mem ber 70 are adapted to be positioned.

It is thought that the operation of this mechanism will be clearly understood from the foregoing description, but briefly stated it is as follows. When the ram is in itsuppermost position the respective valve 59-60 will be positioned as shown in Figure 3 so that any air or fluid which may have been supplied to the cylinders on the top sides of the pistons from the supply, tank 40 will be exhausted by forming communication between the cylinders on the top sides of the pistons and the atmosphere through the pipe 61.

The fluid pressure on the bottom sides of the pistons will then hold the pressure pad 20 in its uppermost position.

As the pressure pad 20 descends the fluid on the bottom sides of the pistons will be.

compressed and air will be sucked into the cylinders on the top sides of the pistons,

through the exhaust *pipe 61 and through the respective pipes 4650. This operation will continue until the pistons have about reached the limit of their lowermost movement at which time the cam 70 will engage the anti-friction roller 69 and rock the member 65 to close the valve 60 and open the valve 59. This will establish communication between the tank or reservoir 40 in the manner described to the top sides of the pistons, thereby\causing the fluid pressure on the bottom sides 'of the pistons to be neutralized or overcome, with the result that the pistons will be locked or held at the limit of their lowermost movement and will be locked against return until the other cam 71 rocks the member 65 in the opposite direction to close the valve 59 and open the valve 60, thereby permitting the fluid pressure on the top sides of the pistons to exhaust to atmosphere so that the pistons and the pressure pad can bereturned by the pressure on the bottom sides of the pistons.

While the preferred form of the invention has been herein shown and described, it is to be understood that various changes may be made in the details of construction and in the combination and arrangement of the several parts, within the scope of the claims, without departing from the spirit of this invention.

What is claimed as new is 1. A cushioning device for presses, said cushioning device embodying a piston and cylinder element relatively movable, means for supplying fluid under pressure to one side of the piston to yieldingly resist such relative movement in one direction, means for supplying said fluid pressure to the other side of the piston to restrain relative movement of said cylinder. and piston, valve mechanism for controlling the direction of flow of said fluid, and means for exhausting the fluid from one side of the piston.

' 2. A cushioning device for presses, said cushioning device embodying a piston and cylinder element relatively movable, means for supplying fluid under pressure to one side of the piston to yieldingly resist such relative movement in one direction, means for supplying said fluid pressure to the other side of the piston to restrain relative movement of said cylinder and piston, valve mechanism for controlling the direction of flow of said fluid, and means automatically operating at a predetermined time in the cycle of operation of the press for exhausting the fluid from one side of the piston.

3. A cushioning device for presses, said cushioning device embodying a piston and cylinder element relatively movable, means for supplying fluid under pressure to one side of the piston to yieldingly resist such relative movement in one direction, means for supplying said fluid pressure to the other side of the piston to restrain relative movement of said cylinder and piston, valve mechanism for controlling the direction of flow of said fluid, and means responsive in its operation to a movable part of the press for exhausting the fluid from one side of the piston.

4. A cushioning device for presses, said cushioning device embodying acylinder and of the piston with said outlet to exhaust the fluid from said other sideof the piston, while the fluid pressure on the first recited side of the piston remains active to produce said relative movement of the cylinder and piston elements.

5. A cushioning device for presses, said cushioning device embodying a cylinder and piston relatively movable, a supply pipe for supplying fluid under pressure to one side of said piston, means connecting said supply pipe with the other side of the piston to supply said fluid pressure thereto to restrain such relative movement, an exhaust outlet, and means automatically operable at a predetermined time in the operation of the press for connecting the said other side of the piston with said outlet to exhaust the fluid from said other side of the piston, while the fluid pressure on the first recited. side of the piston remains active to roduce said relative movement of the cylin er and piston elements.

6. A cushioning device for presses, said cushioning device embodyinga cylinder and piston relatively movable, a pipe for supplymg fluid under pressure to one side of the piston to yieldingly resist such relative movement, a source of fluid supply with which said pipe is connected, a pipe leading to the other side of the a piston, an exhaust, and means operating automatically to connect the second recited pipe with said source of supply to restrain such relative movement of the cylinder and piston elements, the said means also operable automatically to connect the last said pipe to said exhaust to exhaust the fluid from the said other side of the piston. 7. A cushioning device for presses, said cushioning device embodying a cylinder and piston relatively movable, a pipe for supplying fluid under pressure to one side of the piston to yieldingly resist such relative movement, a source of fluid supply with which said pipe is connected, a pipe leading to the other side of the piston, an exhaust, a valve device for connecting the second recited pipe with said source of supply, to restrain such relative movement of the cylinder and piston elements, a valve device for connecting the second recited pipe with said exhaust to exhaust the fluid from said other side of the piston, and means operating automatically to alternately open and close said valves in timed relation to each other.-

8. A cushioning device for presses, said cushioning device embodying a cylinder and piston relatively movable, a supply passage for supplying fluid under pressure to one side of said piston to yieldingly resist such.

' said exhaust, and means responsive in its operation to a movable part of the press for. actuating said valve in timed relation withrespect to each other.

9. A cushioning device for presses, said cushioning device embodying a cylinder and piston relatively movable, a supply passage for supplying fluid under pressure to one side of said piston to yieldingly resist such relative movement, a source of supply of fluid to which said assage is connected, a passage leading to t 1e opposite side of the piston, an exhaust, a valve operable to connect the second said passage with said source of supply to prevent such relative movement and to disconnect the same from said source of supply, a valve operable to connect the second;

said passage with and disconnect the same from said exhaust, a rotatable member having spaced operative portions adapted to alternately actuate said valves in timed relation with respect to each other, and means for actuating said rotatable member.

10. A cushioning device for presses, said cushioning device embodying a relatively movable cylinder and piston, a source of supply of fluid under pressure for yieldingly resisting such relative movement, a passage leading to the other side of the piston, an exhaust, a spring controlled valve device for connecting said source of supply with said passage to maintain said cylinder and piston against such relative movement, a spring controlled valve device for connecting said passage'with said exhaust, a rocker member for alternately actuating said valves, and means operating automatically at predetermined times in the cycle of operation of the press for rocking said rocker member.

11. A cushioning device for presses, said cushioning device embodying a relatively movable cylinder and piston, a source of supply of fluid under pressure for yieldingly resisting such relative movement, a passage leading to the other side of the piston, an exhaust, a spring controlled valve device for connecting said source of supply with said passage to maintain said cylinder and piston against such relative movement, a spring controlled valve device for connecting said passage with said exhaust, a rocker member for alternately actuating said valves, means operating automatically at predetermined times in the cycle of operation of the press for rocking said rocker member alternately in opposite directions, and means for assisting in rocking said member.

12. A cushioning device for presses, said cushioning device embodying a relatively movable cylinder and piston, a source of supply of-fluid under pressure for yieldingly resisting such relative movement, a passage leading to the other side of the piston, an exhaust, a spring controlled valve device for connecting said source of supply with said passage to maintain said cylinder and piston against such relative movement, a

spring controlled valve device for connecting said passage with said exhaust, a rocker member for alternately actuating said valves, means operating automatically at predetermined times in the cycle of operation of the press for rocking said rocker member alternately in opposite directions, and means for assisting in rocking said member, the last said means also operating to retain said rocker member in its rocked position.

13. A cushioning device for presses, said cushioning device embodying a relatively movable cylinder and piston, a source of supply of fluid'under pressure for yieldingly resisting such relative movement, a passage leading to the other side of the piston,

an exhaust, a spring controlled valve device for connecting said source of supply with said passage to maintain said cylin er and piston against such relative movement, a spring controlled valve device for connecting said passage with said exhaust, a rocker member for alternately actuating said valves, means operating automatically at predetermined times in the cycle of operation of the press for rocking said rocker member alternately in opposite directions, and resiliently yielding means operable upon said rocker member for assisting in rocking the same. the last said means also operating to yielding-1y hold in said casing for establishing and closing a tions thereof to alternately actuate the said valves. I

In testimony whereof I have signed my name to this specification, on this 1st day of May, A. D. 1929..

v FREDRICH J. RODE.

connection between said source of supply and the first said passage whereby fluid under pressure will be admitted to said other side of the piston to prevent such relative movement of the cylinder and piston ele-' ments, a valve in said casing for establishing and closing communication between the first said passage and said exhaust passage to exhaust the fluid from said other side. of the piston, and means operable at a predetermined time in the cycle of operation of the press for actuating said valves in timed relation with respect to each other.

15. A'cushioning device for presses, said cushioning device embodying a cylinder and piston element relatively movable, a source of supply for supplying fluid under pressure to said cushion to yleldingly resist said relative movement, a valve casing, a passage leading from said casing to said source of supply, a passage leading from said casing to the opposite side of the piston, an exhaust passage leading from said casing, a valve in said casing for establishing and closing a connection between said source of supply and the first said passage whereby fluid under pressure will be admitted to said other side of the piston to prevent such relative movement of the cylinder and piston elements, a valve in said casing for establishing and closing communication between the first .said passage and said exhaust passage to exhaust the fluid from said other side of the piston, a rotating member, spaced active portions on said member, and means for rotating said member to cause said active por- 

